Boston & Maine Railroad

Boston and Maine Corporation

B&M 1916 system map
Reporting mark	BM
Locale	Maine Massachusetts New Hampshire New York Vermont
Dates of operation	1836–1983
Successor	Guilford Transportation Industries
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Length	2,077 mi (3,343 km)
Headquarters	Boston, Massachusetts

The Boston and Maine Corporation (reporting mark BM), known as the Boston and Maine Railroad (B&M), was a former U.S. Class I railroad in northern New England. It became part of what is now the Pan Am Railways network in 1983.

At the end of 1970 B&M operated 1,515 route-miles (2,438 km) on 2,481 miles (3,993 km) of track, not including Springfield Terminal. That year it reported 2744 million ton-miles of revenue freight and 92 million passenger-miles.

The Andover and Wilmington Railroad was incorporated March 15, 1833, to build a branch from the Boston and Lowell Railroad at Wilmington, Massachusetts, north to Andover, Massachusetts. The line opened to Andover on August 8, 1836. The name was changed to the Andover and Haverhill Railroad on April 18, 1837, reflecting plans to build further to Haverhill, Massachusetts (opened later that year), and yet further to Portland, Maine, with the renaming to the Boston and Portland Railroad on April 3, 1839, opening to the New Hampshire state line in 1840.

The Boston and Maine Railroad was chartered in New Hampshire on June 27, 1835, and the Maine, New Hampshire and Massachusetts Railroad was incorporated March 12, 1839, in Maine, both companies continuing the proposed line to South Berwick, Maine. The railroad opened in 1840 to Exeter, New Hampshire, and on January 1, 1842, the two companies merged with the Boston and Portland to form a new Boston and Maine Railroad.

On February 23, 1843, the B&M opened to Agamenticus, on the line of the Portland, Saco and Portsmouth Railroad in South Berwick. On January 28 of that year the B&M and Eastern Railroad came to an agreement to both lease the PS&P as a joint line to Portland.